I should hope that open source developers are exclusively using open source models that are trained on open source projects.
I mean, I would think, at least. It seems to me that most of the people in charge of big projects are usually FOSS purists.
That's part of the reason why AI scrapers are breaking the small web. FOSS purists really have no significant defense against it aside from Anubis.
Real DoS protection comes from capacity, which costs serious dollars, especially in this day and age where botfarms can be hired by the hour for rather cheap and record-breaking attacks seem to happen like monthly.
The alternative is using a CDN, but there are none that align with FOSS ideals. And for CDNs to be really effective, you need them to break open TLS and handle the decrypted traffic, which raises privacy concerns on top.
But anyways...most license agreements would make it a requirement that if you're using an open-source model, that it be properly attributed, right?